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Biomedical subjects

H Ohtani

Publications and source records attributed to H Ohtani.

At least 253 records · Page 14Linked to original sources
PubMed1994

Infrequent stromal expression of gelatinase A and intact basement membrane in intraductal neoplasms of the pancreas.

BACKGROUND/AIMS: Basement membrane disruption is a characteristic of invasive carcinoma. Gelatinases (also called type IV collagenases) that degrade type IV collagen are believed to play an important role in tumor invasion and metastasis. Intraductal neoplasm (IDN) of the pancreas is a unique tumor that grows intraductally with an infrequent stromal invasion. However, in IDN, basement membrane anomaly and gelatinase expression have not been clarified. The aim of this study was to examine the relationships between basement membrane disruption and the expression of gelatinase A in relation to the biological behavior of IDN or pancreatic duct cell carcinoma (DCC). METHODS: Disruption of basement membrane and expression of gelatinase A were immunohistochemically investigated in 14 cases of IDN and 16 cases of DCC. RESULTS: Basement membrane was intact in all cases of IDN, whereas focal to severe disruption was observed in DCC. Stromal expression of gelatinase A was higher in DCC than in IDN, and the intensity of expression was related to the degree of disruption of the basement membrane in DCC. CONCLUSIONS: Stromal expression of gelatinase A and disruption of basement membrane, common characteristics of invasive cancer, were not prominent in IDN. This may be related to the benign biological behavior of IDN.

Aged↗
PubMed1994

Effect of pravastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, on hepatic cholesterol 7 alpha-hydroxylase, acyl-coenzyme A: cholesterol acyltransferase, and bile lipid secretion in the hamster with intact enterohepatic circulation.

The effects of administration of pravastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, on hepatic cholesterol 7 alpha-hydroxylase and acyl-coenzyme A: cholesterol acyltransferase (ACAT) activities and bile lipid secretion were investigated in Syrian golden hamsters. Continuous administration of pravastatin induced no significant changes in hepatic cholesterol content, ACAT and cholesterol 7 alpha-hydroxylase activities, or bile lipid and acid composition. Abrupt withdrawal of pravastatin induced increases in hepatic cholesterol content and ACAT activity and no change in hepatic cholesterol 7 alpha-hydroxylase activity, and increased cholesterol saturation in bile. Hepatic cholesterol 7 alpha-hydroxylase activity paralleled hepatic mRNA levels of this enzyme. These results suggest that a change in hepatic cholesterol metabolism induced by continuous administration of pravastatin maintains a constant net balance of hepatic cholesterol content. In addition, the drug has no deleterious influence on metabolism of bile lipids and acids and related enzymes, except for a transient increase in cholesterol saturation in bile induced by an inappropriate increase in hepatic cholesterol content and a lack of response of cholesterol 7 alpha-hydroxylase activity to changes in hepatic cholesterol content upon abrupt withdrawal of pravastatin.

Animals↗
PubMed1994

Benzodiazepine concentrations in sera determined by radioreceptor assay for therapeutic-dose recipients.

Using a radioreceptor assay, the authors determined benzodiazepine concentrations in sera of the 168 subjects who had been taking one or more benzodiazepines daily without showing excessive or adverse effects. In most of the recipients (150 of 168, 89.3%) of the sleep-inducing, anxiolytic, sedative, or anticonvulsant benzodiazepines, the concentrations were below 500 ng/mL in diazepam equivalents. Only two recipients (1.2%) showed concentrations above 1,000 ng/mL. These data will be useful in managing benzodiazepine therapy and in determining a diagnosis of benzodiazepine overdose.

Adolescent↗
PubMed1994

Molecular weight analysis of cow's milk antigens in neonate sera.

Some food antigens (Ag) can be detected in serum immunoglobulin G (IgG) antibodies (Ab) following ingestion. These Ag may thus be essential for inducing the production of IgE or IgG antibodies, which may in turn lead to the onset of atopic diseases such as atopic dermatitis, allergic rhinitis and asthma. The molecular weights (MW) of these Ag have yet to be determined. To select samples for MW analysis of circulating food Ag, we measured the concentrations of cow's milk (CM) Ag in the sera of 88 neonates by radio-immunoassay. They were found present in 20 samples of the sera. Twelve of the samples were analyzed for Ag MW by immunoblotting. Several bands appeared for one of the samples. Their MW were < 13,000 and no native CM proteins could be detected.

Animals↗
PubMed1994

Developmental stage- and spermatogenic cycle-specific expression of transcription factor GATA-1 in mouse Sertoli cells.

GATA-1 is an essential factor for the transcriptional activation of erythroid-specific genes, and is also abundantly expressed in a discrete subset of cells bordering the seminiferous epithelium in tubules of the murine testis. In examining normal and germ-line defective mutant mice, we show here that GATA-1 is expressed only in the Sertoli cell lineage in mouse testis. GATA-1 expression in Sertoli cells is induced concomitantly with the first wave of spermatogenesis, and GATA-1-positive cells are uniformly distributed among all tubules during prepubertal testis development. However, the number of GATA-1-positive cells declines thereafter and were found only in the peripheral zone of seminiferous tubules in stages VII, VIII and IX of spermatogenesis in the adult mouse testis. In contrast, virtually every Sertoli cell in mutant W/Wv, jsd/jsd or cryptorchid mice (all of which lack significant numbers of germ cells) expresses GATA-1, thus showing that the expression of this transcription factor is negatively controlled by the maturing germ cells. These observations suggest that transcription factor GATA-1 is a developmental stage- and spermatogenic cycle-specific regulator of gene expression in Sertoli cells.

Animals↗
PubMed1994

Nuclear magnetic resonance study and secondary structure determination of the antibiotic peptide, aibellin.

Aibellin is a 20-residue peptide antibiotic that has been isolated from the fungus Verticimonosporium ellipticum. Sequence-specific assignment of the 1H- and 13C-NMR signals of aibellin in a methanol solution was achieved by using the two-dimensional NMR technique. Furthermore, its secondary structure was characterized by circular dichroism (CD) and NOESY spectra. The observed NOEs, 3JNHC alpha H coupling constants and amide hydrogen-deuterium (H-D) exchange rates show that the peptide consisted of two alpha-helices and a bent structure around a Pro-14 residue.

Amino Acid Sequence↗
PubMed1994

Structural elucidation of aibellin, a new peptide antibiotic with efficiency enhancing activity on rumen fermentation.

A new peptide antibiotic, aibellin, that had the efficiency enhancing activity on rumen fermentation, was isolated from the culture broth of the fungus, Verticimonosporium ellipticum D1528, and its primary structure was elucidated from spectrometric analysis and chemical degradation. Aibellin is a 20-residue peptaibol, and it has a unique structural feature in the novel C-terminal amino alcohol. Moreover, aibellin is the first peptaibol that possesses two acidic amino acids in the C-terminal region and a Phe residue in the middle of the sequence.

Amino Acid Sequence↗
PubMed1994

Structural studies of new macrolide antibiotics, shurimycins A and B.

The structures of new antibiotics, shurimycins A and B produced by Streptomyces hygroscopicus A1491, were elucidated from the physico-chemical properties, 2D NMR techniques and chemical degradation experiments to be 36-membered macrolides related to azalomycins, scopafungin and guanidylfungins. Shurimycins were active against fungi and Gram-positive bacteria.

Anti-Bacterial Agents↗
PubMed1994

[Changes in C100-3, and N14 antibodies in patients with chronic hepatitis C treated with interferon].

In interferon therapy for chronic hepatitis type C, we assayed C100-3 and N14 antibodies, and also determined IgM-C100-3 and IgM-N14 antibodies as well as HCV-RNA. N14 antibody was assayed by an end point titer method. In patients responding to interferon therapy, C100-3 and N14 antibody titers were decreased and became negative. In patients irresponsive to interferon therapy, C100-3 antibody titers were hardly changed, while N14 antibody titers were markedly increased. IgM-C100-3 and IgM-N14 antibody levels were significantly higher in the patients non-responding to interferon therapy than in those responding to interferon therapy. The daily assays of C100-3 and N14 antibody titers are considered useful in judging the effectiveness of interferon against chronic hepatitis type C.

Antigens, Viral↗
PubMed1994

CD34+ spindle-shaped cells selectively disappear from the skin lesion of scleroderma.

BACKGROUND AND DESIGN: The pathogenesis of scleroderma is still unknown. Recently, it has become possible to identify different subpopulations of dermal spindle-shaped cells using anti-CD34 and anti-factor XIIIa antibodies. To elucidate whether entire populations of dermal fibroblasts or only a subpopulation of cells are involved in the fibrosis of scleroderma, we compared the staining pattern of these antibodies and antiprocollagen antibody in paraffin-embedded skin sections from the lesions of 27 patients with scleroderma and 15 patients with other collagen diseases and from normal skin of 17 subjects. Cryostat sections from both involved and uninvolved skin of four patients with scleroderma were also stained with anti-CD34, anti-factor XIIIa, and anti-proline-4-hydroxylase antibodies. RESULTS: CD34+ cells were few or absent in the lesions of scleroderma, while a number of CD34+ cells were found in the lesions of other collagen diseases and in normal skin. In contrast, large numbers of factor XIIIa-and procollagen-positive cells were noted in the lesions of scleroderma. Even in the study in which cryostat sections were used, CD34+ cells were totally absent from the lesions of scleroderma, while there were numerous proline-4-hydroxylase-positive cells. Furthermore, although detectable in the clinically uninvolved skin of these patients, CD34+ cells were less frequent and more slender than those in normal skin. CONCLUSION: Immunohistologic staining with anti-CD34 and other antibodies to dermal spindle-shaped cells demonstrated a selective disappearance of CD34+ spindle-shaped cells from the lesions of scleroderma. It suggests that CD34+ cells might be important target cells in the autoreactive phenomenon in scleroderma.

Adolescent↗
PubMed1994

Effect of temperature on molecular structure of cyclosporin A.

By reversed-phase HPLC and NMR spectroscopy, cyclosporin A (CsA) was found to have several molecular structures in polar solvents. In addition, temperature change was found to cause the structural alteration in the polypeptide chain of CsA. Although CD spectrum of CsA in ethanol/water was indicative of the beta-turn structure rather than the beta-sheet structure of the polypeptide chain, the temperature-dependent structural changes were undetectable by CD spectroscopy. The inhibitory effect of CsA on peptidyl prolyl cis-trans isomerase activity was suppressed with elevation in temperature. These results indicate that the alteration in the tertiary structure of CsA plays an important role for the binding capability to its receptor and the immunosuppressive activity.

Chromatography, High Pressure Liquid↗
PubMed1994

[A 65-year-old woman with headache, facial pain, and progressive multiple cranial neuropathy].

We report a 65-year-old woman with progressive multiple cranial neuropathy. She had been suffered from bronchial asthma since 1979 for which prednisolone had been prescribed. She noted an onset of pain around her nose in October, 1989, which extended into the periorbital regions bilaterally. In February, 1990, she was treated with stellate ganglion block and trigeminal nerve block; these treatments partially alleviated her pain. In May of 1991, she noted a difficulty in swallowing solid foods. In November of the same year, she developed right facial paresis; two weeks later, she noted numbness in her left face, and was hospitalized to our service on December 16, 1991. On admission, she was afebrile and general physical examination was unremarkable except for piping rales in her both lung fields. On neurologic examination, she was alert and oriented to all spheres; higher cerebral functions were intact. In the cranial nerves, her olfactory sense was lost bilaterally; her vision was markedly diminished bilaterally only to recognize hand movements; the optic fundi appeared normal; the pupils were isocoric and reacted to light promptly. The extraocular muscles were moderately weak to most of the directions more on the left; no nystagmus was present. Facial sensation was diminished bilaterally; the jaw deviated to right; right facial paresis of peripheral type was present; her hearing was diminished bilaterally more on the right. The movement of the soft palate was diminished on the right side; dysphagia was present; her voice was horse; the gag reflex was diminished. The sternocleidomastoid muscle was weak bilaterally; the tongue appeared normal. Examination of gait was differed because of headache, however, no apparent motor weakness was present. No ataxia or involuntary movement was noted. Deep reflexes were normally elicited and symmetric. Plantar response was flexor. Sensation in the extremities was intact. Kernig's sign was positive at 70 degree leg extension; eyeball tenderness was also present bilaterally, however, no nuchal stiffness was noted. Following abnormalities were present in the laboratory examination: WBC 11,400/microliters, ESR 50 mm/hr, CRP 6.1 mg/dl. The lumbar CSF was under a normal pressure containing 29 WBC/microliters (neutrophils 7, lymphocytes 20, others 2), 67 mg/dl of protein, and 53 mg/dl of sugar; cultures for acid-fast bacilli as well as for other bacteria were negative; no malignant cells were found. A cranial CT scan revealed an isodensity mass in the orbit and ill-defined low density areas in the white matters of the frontal lobes.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1994

[Detection of Candida albicans by PCR].

Detection of Candida albicans by the polymerase chain reaction (PCR) was conducted. Oligonucleotide primers to amplify a 180 bp fragment on the beta-tubulin gene of C. albicans were synthesized. PCR was conducted using standard strains (14 species and 32 strains) and strains isolated from clinical samples (8 species and 12 strains) in Kitasato University Hospital. The PCR specifically amplified DNA from C. albicans of all standard strains and neither any other Candida, other fungal, bacterial nor human DNA. In three samples of clinically isolated C. albicans strains, the positive bands were also detected. This PCR procedure is more specific and rapid than the conventional culture method and is applicable to clinical diagnosis of the C. albicans infections.

Candida albicans↗
PubMed1994

[Acute monoblastic leukemia (M5a) with dysmegakaryocytopoiesis associated with t(16;21) (p11;q22)].

We report a 24-year-old woman who had acute monoblastic leukemia associated with t(16;21) (p11;q22). She was referred to our hospital in April 1992 because of high fever and hemorrhagic diathesis. Physical examination on admission showed no hepatosplenomegaly. The hemoglobin was 5.1g/dl, platelet count 1.7 x 10(4)/microliters, the white blood cell count 18,700/microliters. Bone marrow aspirate showed that 86% of nucleated cells were monoblasts which were positive for peroxidase and alpha-naphtyl butyrate esterase. She was diagnosed as having M5a. Dysmegakaryopoiesis, such as micromegakaryocytes and megakaryocytes with multiple small separated nuclei, was seen in the bone marrow. Chromosomal analysis revealed t(16;21). Complete remission was achieved after two courses of BHAC-DMP therapy, but dysmegakaryopoietic features remained. She relapsed in September 1992. Review of the literature and this patient indicate that acute nonlymphocytic leukemia with t(16;21) is associated with multilineage leukemic differentiation.

Adult↗
PubMed1994

[A 78-year-old man with progressive gait disturbance, dysphagia, and dementia].

We report a 78-year-old man with progressive gait disturbance, dementia, and dysphagia. He was apparently well until 75 years of age in 1989 when he had an insidious onset of gait disturbance. In October of 1991, he was treated with levodopa and amantadine HCl in another hospital, but he developed visual hallucination right after these medications, and the drugs were discontinued. He also developed difficulty in swallowing with frequent aspiration pneumonia. He was admitted to our hospital on January 13, 1992. On admission, the patient was chronically ill Japanese man; his blood pressure was 118/70 mmHg, body temperature 35.4 degrees C, and heart rate 72 and regular. No anemia or jaundice was noted; lungs were clear and no heart murmur was audible. The abdomen was flat but rigid to palpation without tenderness; no organomegaly was noted. On neurologic examination, he was alert but disoriented to all spheres; he was apparently demented and the score of the mini-mental test was 11. He did not appear to have aphasia or apraxia. Cranial nerves appeared intact, but he had a mask-like face and a slight limitation in the upward gaze; his voice was small. He was unable to stand or walk; he showed marked akinesia and moderate rigidity in his neck and the trunk. Deep reflexes were generally elicited normally or slightly weakly. Plantar response was extensor on the left and flexor on the right. No grasp reflex was present. Sensory examination showed questionable loss of touch in the glove- and -stocking distribution.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Recovery of viability in triploid hybrids between Japanese and European water frogs, and their reproductive capacity.

Diploid and triploid hybrids, consisting of the various combinations of chromosome set and cytoplasm between Rana nigromaculata and Rana lessonae, were generated in order to study their viability and reproductive capacity. Reciprocal diploid hybrids and allotriploids, which had two lessonae genomes and one nigromaculata genome in nigromaculata cytoplasm, all died without closing their neural folds. Allotriploids, which had two nigromaculata genomes and one lessonae genome in nigromaculata cytoplasm, all grew into healthy mature males in 12.4% (21 frogs) of zygotes. Following the elimination of lessonae chromosomes, ten of these males produced many spermatozoa containing a haploid set of nigromaculata chromosomes. Other allotriploids, which had either one nigromaculata genome and two lessonae genomes or two nigromaculata genomes and one lessonae genome in lessonae cytoplasm, exhibited slightly improved viability.

Animals↗
PubMed1993

Erythroid transcription factor GATA-1 is abundantly transcribed in mouse testis.

The transcription factor GATA-1 is a fundamental regulator of genes in haematopoietic cell lineages and belongs to a family of factors that bind to the consensus sequence WGATAR. The GATA motif was originally identified in cis-regulatory regions of globin and other erythroid-specific genes, but the range of genes controlled by the GATA factors has since expanded. Members of the GATA transcription factor family share a conserved zinc-finger DNA-binding domain, but the expression profile of each GATA factor is distinct. Here we show that a testis form of murine (m)GATA-1 messenger RNA is transcribed from a promoter located 5' to the erythroid first exon, and the remaining exons (which encode the mGATA-1 protein) are used in common by both testis and erythroid transcripts. We use an anti-mGATA-1 monoclonal antibody to show that the factor expressed in erythroid cells is the same as that found in the seminiferous tubules of murine testis. The GATA-1-expressing cells in 10-week-old testis were found only in contact with the basement membrane of seminiferous tubules, suggesting that GATA-1 regulates genes during the earliest stages of spermatogenesis.

Aging↗